package lanqiao;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;

public class time {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        long l = scanner.nextLong();
        Date date =new Date(l);
        SimpleDateFormat sd = new SimpleDateFormat("HH:mm:ss");
        System.out.println(sd.format(l));
    }
}
